Back rest for chairs



Oct. 17, 1944; 5. J. MURPHY ,7

BACK REST FOR CHAIRS I Filed April 15, 1942 [II/IA Ill Patented Oct. 17, 1944- BACK REST FOR CHAIRS Stephen J. Murphy, Owensboro, Ky., assignor to Murphy Chair Company, Incorporated, Owensboro, Ky., a corporation of Kentucky Application April 15, 1942, Serial No. 439,134

1 Claim.

The present invention relates to back rests for chairs, and more particularly to an adjustable back rest of the type attached to the back portion of ofiice chairs such as are used by typists.

One Of the objects of the invention is to provide supporting brackets adapted to be readily adjusted vertically as well as horizontally and to which the back rest is pivoted so that the occupants back is comfortably supported.

Another object of the invention is to eliminate costly metal fixtures by providing a simple bracket made up of a minimum of parts, yet effective to accomplish the purpose for which it is designed.

Other objects will be apparent from the following description taken in connection with the accompanying drawing, in which Fig. 1 is a perspective of a chair in which the invention is embodied;

Fig. 2 is a fragmentary side elevation, partly in section, of a chair illustrating the manner in which the back rest brackets are attached thereto;

Fig. 3 is a partial section taken on line 3-3 of Fig. 2;

Fig. 4 is a section taken on line 44 of Fig. 3;

Fig. 5 is a fragmentary side elevation, partly in section, of an upright and the plate attached thereto; and

Fig. 6 is a section taken on line 6-6 of Fig. 4.

In the drawing, the chair includes the usual seat portion I0 and uprights I I, the latter being connected by cross-piece I2 to constitute the back frame 01f the chair. Back rest l3 extends forwardly of the back frame and is connected to each of the uprights by two similar slotted brackets I4 pivoted to angle brackets I5, the latter being fastened to the back rest. The upper portion of each upright is provided with a longitudinal recess I6, a plate I! having an elongated slot I8 therein being secured to each upright and covering the recess therein. Slot I8 is substantially coextensive with recess I6. Within each of the recesses I6 is the head I9 of bolt 20, the head of the bolt having a Width substantially greater than that of slot I8. This bolt has a squared portion 2I cooperating with slot I8 to permit the bolt to slide vertically therein, but which prevents turning of the bolt. Bolt 20 also has a threaded portion 22 passing through slotted bracket I4 and adapted to ac commodate washer 23 and thumb nut 24. It is to be noted that the abutting faces of each of the members I4 and I! are provided with parallel V-shaped grooves 25, those in bracket I4 extending longitudinally of the bracket while those in plate I1 extend transversely thereof. Thus, all of the grooves are substantially horizontal so that, when thumb nut 24 is tightened, the brackat and plate are firmly held against relative rotation.

From the [foregoing description of the invention, it is apparent that, by loosening the thumb nuts at opposite sides of the back frame, the bolts may be moved either upwardly or downwardly for vertical adjustment thereof. At the same time, brackets l4 may be moved rearwardly or forwardly to adjust the position of the back rest with respect to the back frame. In this manner the rest is positioned to the desired height, and its relation forwardly of the back frame fixed to suit the occupant. When the thumb nut is then tightened, the back rest remains in the desired position. Since the back rest is likewise pivoted to bracket I4, it is apparent that it adapts itself to the position of the occupant and provides proper sitting posture and comfort.

Having described my invention, what I claim as new and desire to secure by Letters Patent is:

The combination with a chair having back uprights, said uprights each having a vertical elongated recess, of a plate covering each recess and having a slot substantially coextensive with said recess, a pair of brackets each having an elongated slot therein, a back rest secured to said brackets, bolts extending through said slots and adjustably slidable with respect thereto, each said bolt having its head in each said recess, the width of said head being substantially greater than that of the slot in said plate, each said bolt having a squared portion cooperating with said plate slot to prevent rotation of said bolt, said brackets being disposed at right angles to said plates, said plates each having transverse grooves and said brackets each having longitudinal grooves cooperating with the grooves in said plates to prevent relative rotation thereof, and means on said bolt for clamping said bracket to said plate.

STEPHEN J. MURPHY. 

